Railway-signal.



R. A. BALDWIN.

RAILWAY SIGNAL.

(Application filed. Dec. 9, 1901.)

(No Model.)

PmWHH'E m: Nonms PETERS co PH5TO-L|YNO., WASHINDYON, n. c.

Ntrnn STATE PATENT OFFICE.

ROLLIN A. BALDWIN, OF SOUTH NORWALK, CONNECTICUT.

RAILWAY-SIG NAL.

SPECIFICATION forming part of Letters Patent No. 712,754, dated November4, 1902.

I Application filed December 9, 1901. Serial No. 85,188. (No model.)

To all whont it ntcty concern:

Be it known that I, RoLLIN A. BALDWIN, a citizen of the United States,residing at South Norwalk, in the county of Fairfield and State ofConnecticut, have invented certain .new and useful ImprovementsinRailway-Signals, of which the following is a full, clear, and exactdescription.

This invention is an automatic system of railroad-signals designedespecially to protect single-track roads and to meet the requirements oftrolley and other roads where it is sometimes desirable to allow morethan one car to be in a block at the same time and yet protect them all.

The invention comprehends the appara' tus and circuits hereinafterdescribed andclaimed.

In the accompanying drawings, Figure 1 is a diagram of the circuits ofone block of the system. Fig. 2 is an elevation of the signalmovingmagnets. Fig. 3 is a view of the signal-arm or semaphore with the frontremoved. Fig. 4 is a section'of the semaphore and plan of the boxcontaining the mechanism for moving it, and Fig. 5 is a detail of thecircuit-controller.

The semaphore used in my improved system, although not claimed herein,is illustrated in Figs. 3 and 4, wherein the same consists of anelongated box or tube a, hung on a shaft b and having at its axial endan enlarged chamber a to accommodate an electric lamp 0. The lamp isfixed to a boss 0, surrounding the axis b, and does not move with thearm. Immediately behind the lamp is a reflector which projects the raysof'light through the hollow arm. In the front of this arm is atransparent face 0. which extends nearly its full length, and back ofthis is arranged a corrugated reflector a upon which the rays of lightfrom the lamp are reflected outward through the glass front and at rightangles thereto. The glass front may be translucent in order to make aneven surface of light, and, if preferred, the glass front may besubstituted by a series of prisms, such as are used inlighthouse-lanterns to receive the rays of light directly and throw themoutward at right angles to the plane of the arm. An arm constructed inthis manner is adapted for two or more positions, and its advantage isthat at night it will serve both as a position and as a color signal,while in the daytime it will serve as a position-signal. The enlargedchamber at the base ofthe arm is to permit it to move to its angularposition without interfering with the lamp; but obviously the lamp mightbe made to move with the arm, if it be so desired. The weight of the armshould be counterbalanced by a weight w in the usual manner.

The shaft Z) passes into a box B, wherein it is provided with suitablebearings, and carries a semicircular disk or plate I), through thecenter point of which the shaft passes. Beneath this disk are mountedtwo independent electromagnetic coils e and f,respectively, in the formof solenoids, their cores being indicated by e and f and normallyresting be low the magnets upon a suitable support g. These cores are inthe plane of the disk b, and when one of the coils is energized by thepassage of current through it the core is pulled upward, strikes theunder side of the disk and tilts it until its other side rests upon ornearly upon the head of the other core. If the other coil is thenenergized, the position of the disk is reversed. In this manner theposition of the semaphore is shifted.

In order that the circuits of the several magnets may be closedautomatically by the trolley, I mount a short length of metallic hood habove the wire and insulated therefrom in a position wherethe'trolley-wheel will come in contact with it at the same time it ispassing over the neighboring portion of the trolley-wire. This deliverscurrent from the wire through the wheel to the hood, and from the hood aconductor is led to the signal.

Referring now to Fig. 1, the trolley-wire I of a single-track road isillustrated. It is branched at intervals into loops '5 and t",where theturnouts of the track occur. The distance between any two turnouts isusually a block in the signal system, one of the blocks beingillustrated in the figure. At each station or turnout I locate three ormore signals, two of which are for cars going in the two directions,while the third and any others that may be used are special signals, aswill be hereinafter described Each signal mechanism consists of the twomagnets e andfand the semaphore a. The signal P at one end of the blockis electrically connected with the signal P at the other end. Likewisesignal Q is connected with Q, and R is connected with R. Signals P and Pare of different colors-say, while and red. Signals Qand Q are also ofdifferent colors, but reversed with respect to the first twot hat is,red and white. Signals R and R are both red. These colors are obtainedat night by colored glass and in the daytime by the color of the painton the frame of the arm. The contacts h are adjusted to the trolley-wireat each turnout, each side of the loop having one of the conlacts, asindicated at 1, 2, 3,and 4. In addition to this there are specialcontacts for the special signals, (indicated by 5, 6, 7, and 8.) Thesespecial contacts instead of being applied to the main trolley-wire areapplied to spurs 0, which branch from the main trolleywire on each sideof the loop.

The operation is as follows: When no car is on the block, all signalsare down or in the safety position. Car S on entering the block willclose a circuit from contact 1 through the wire 9, magnetf of the signal1, wire 10, magnetfof the signal P, and ground. This will throw bothsignals P and P to the danger position. Signal P, being white, willindicate to another car following the first that the car ahead is movingaway from it and that it can,

if necessity demands, cautiously follow with-' out danger of a head-oncollision. Signal P, however, being red, indicates to a car approachingfrom the opposite directionsay at Uthat the car on the block isapproaching and the block is not to be entered under any circumstances.\Vhen the first car S reaches the point T, a circuit is closed fromcontact 2, through wire 11, magnet e of signal P, wire 12, and magnet eof signal P, to ground, thus causing the semaphores to move to thesafety position and showing the block to be clear. Another car followingS can then enter the block and perform the same operation, or a car at Ucan enter the block from the opposite direction, in which case a circuitwill be closed from contact 3 by wire 13, magnet e of signal Q, wire 14,magnet e of signal Q and to ground. This would throw the white signal Qand the red signal Q to danger and protect the car U in the same mannerthat car S was protected, as before described. Thus the signals P and Pare for cars traveling in one direction, while Q and Q are for carstraveling in the opposite direction, the color of the signal in eithercase showing the other cars the direction in which the carin the blockis moving. In case one car immediately follows another onto the block atsuch a short distance as to be always in sight of each other, the carscan proceed in safety through the block, the first one setting anddropping the signals in the same manner as before described, the secondcar not interfering with the signals, because it would merely energizethe same magnets the second time, and their solenoids would not have anyeffect on the disk. If, however, one or two cars, as X and Y, are in theblock but out of sight of, a car at V and the latter found it necessaryto proceed onto the block, following the others, the motorman V wouldknow that cars X and Y were moving away from him by the fact of thewhite signal at Q, and then, for his own protection, he would shift thetrolley from the main line onto the spur 0 and proceed cautiously. Car Vwould thus close a circuit from contact 7 by wire 15 to magnet e ofsignal R, wire 16, magnet e of signal R to ground. A red signal wouldtherefore be set at each end of the block in addition to the white andred signals set by the car Y. Thus after car Y and its follower X haveleft the block and dropped the signals Q and Q, car V would still beprotected by its own red signals. The special signals are both red or ofthe same color as those signals which indicate that the car isapproaching the end of the block where the signal is located, so that noother car will enter the block under any circumstances until car V isout. The peculiar shape of the disk holds the signal in any position towhich it has been set by the magnets, because the center of gravity istransferred to the opposite side of the center each time the disk isshifted. In case a circuit gets out of order during the passage of a carover the block the signal will remain at danger until repairs are made.In trolley systems cars follow each other on such short headway thatinjury to the circuits or apparatus is not liable to take place in theshort intervals when no car is on a block. Hence the safety of thesystem is assured.

Having described my invention, I claim-- 1. In a railway-signal, thecombination of a signal-arm, a disk or plate pivoted at the middleof oneedge and adapted to move the arm, and two solenoids whose armatures areadapted to strike the plate on opposite sides of its pivot to therebyoscillate it, substantially as described.

2. In a railway-signal, a circuit extending from one end of a block tothe other, a signal at each end comprising an arm and twoelectromagnets, one magnet of each signal being included in saidcircuit, and a second circuit including the other two magnets,substantially as described.

3. In a railway-signal, a circuit extending from one end of a block tothe other, a signal at each end comprising an arm and twoelectromagnets, one magnet of each signal being included in saidcircuit, a second circuit including the other two magnets, and meanswhereby a car will automatically energize one circuit when it enters theblock, and energize the other circuit when it leaves the block,substantially as described.

4. In a signal system, for trolley-railways, the combination of the mainor trolley conductor, a signal-circuit, a spur-conductor and a contactdevice applied to the spur and connected with the signal-circuit,whereby the trolley will control the latter, substantially as described.

5. In a block-signal system for trolley-railways, the combination of themain or trolley stantially as described.

6. In an automatic block-signaling system, a block provided at each endwith a signal automatically set by the cars or trains and indicating thedirection of movement of a car or train in the block, in combinationwith other signals located at the respective ends of the block andadapted to be operated by a second car or train following the first intothe block but giving no indication of the direction of movement of thesaid second car.

7. In an automatic block-signaling system, an electric circuit includinga signal at each end of the block, means wherebya car entering the blockwill automatically set said signals, a' second electric circuitincluding two other signals at the respective ends of the block andmanually-controlled devices operated on the passage of a second car forsetting the said second set of signals.

8. In an automatic block-signaling system, an electric circuit includinga signal at each end of the block, means whereby a car entering theblock will automatically set said signals, a second electric circuitincluding two other signals at the respective ends of the block, anelectric-railway conductor, a spur therefrom at the entrance of a block,a circuit-closer applied to said spur and controlling the said secondelectric circuit, an electric car and a trolley adapted to cooperatewith the spur when desired.

In witness whereof I subscribe my signature in presence of twowitnesses.

ROLLIN A. BALDWIN.

Witnesses:

JACOB M. LAYTON, JAMES PAUL.

